The present invention relates in general to exercise equipment, and in particular to a new and useful portable exercise device which comprises a piston assembly which is slidably mounted in a pressurized cylinder assembly. Handles connected to the respective assemblies can be used to press the assemblies together against the resistance of air pressure in the apparatus.
Several portable exercising devices are known which comprise opposite handles which can be grasped and either pressed together or pulled apart for exercising the arms and other parts of the body.
U.S. Pat. No. 767,008 of 1904, discloses an exercise device which comprises a cylinder connected to one handle and a piston which is slidably mounted in the cylinder, connected to another handle. Valves are provided in the cylinder on opposite sides of the piston for metering a flow of air into and out of the cylinder. By regulating the resistance to air flow through the valves, the force needed to move the handles apart and together is adjusted. A similar arrangement is disclosed in U.S. Pat. No. 4,290,599. A portable exercise device which contains oil rather than air as the flowing fluid is disclosed in U.S. Pat. No. 4,148,479.
U.S. Pat. No. 4,333,645 discloses another example where the throttled flow of air is used in a piston and cylinder combination, to produce an exercise apparatus.
U.S. Pat. No. 3,944,221 discloses an exercise apparatus which includes a cylinder connected to one handle and a piston connected to an opposite handle the piston being slidably mounted within the cylinder. Check valves are utilized to admit air into the cylinder as the piston is moved back and forth. The pressure in the cylinder thus increases with each stroke to increase the resistance of the handles to movement. Push button releases are provided to discharge the built up air pressure so that a new exercise cycle can begin.
None of the references disclose the use of a normally closed inflating valve in an exercise apparatus comprising a piston and cylinder combination, sc that the static pressure within the apparatus can be increased to a selected level for conducting exercises at that level.